Core C: Animal Production and Specimen Preparation The goal of this core is to produce all of the mice needed in the Program Project, to assess their health status, and to generate the biopsy and necropsy specimens needed by each of the component projects within the program. Specific Aims include: 1. Breeding the 600 UM-HET3 mice of Population 1. 2. Providing tail tip DNA specimen for genotyping by Genotyping Core. 3. Providing biopsy specimens (blood cells, plasma, skin, etc.) needed at defined ages by Projects 1 and 5. 4. Providing body weight data at 3 month intervals to the Analysis ore. 5. Sacrificing each mouse in Population 1 at 18 months of age, and providing tissue specimens needed by each of the projects for physiological and/or biochemical analysis. Data on pathological lesions will be provided to each investigation and to the Analysis Core for use as a co-variate or exclusion criterion in statistical tests. 6. Producing the 180 mice in Population 2 (half of which are selected for genetic alleles associated with prolonged lifespan), and providing biopsy and necropsy specimens for these mice to each project. 7. Breeding UM-HET3 mice needed at various ages as controls by several of the component projects. The Core will be directed by Dr. Richard Miller, who will be assisted by the effort of a half-time research technician. All mice will be housed in the specific pathogen free vivarium of the newly opened Cancer Center and Geriatrics Center Building, and will be protected from infectious illness by use of individual micro-isolator caging. Husbandry procedures in use by the Geriatrics animal colonies have been able to maintain documented specific-pathogen free status since 1993, and should ensure a supply of high quality research animals for use in this program.